### Another GFN-262144 Find!!

On 16 February 2020, 01:13:42 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime:

**9812766^262144+1**The prime is 1,832,857 digits long and enters Chris Caldwell's**The Largest Known Primes Database**ranked 15th for Generalized Fermat primes and 87th overall. The discovery was made by Tom Greer (**tng***) of the United States using an NVidia GeForce RTX 2070 in an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Core x64 Edition. This GPU took about 17 minutes to complete the probable prime (PRP) test using GeneferOCL2. Tom Greer is a member of the**Sicituradastra.**team. The prime was verified on 16 February 2020, 01:39:49 UTC by Viktor Svantner (**Viktor Svantner**) of the Czech Republic using a GeForce GTX 1080 Ti in an AMD Ryzen Threadripper 2990WX 32-Core Processor with 128GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 22 minutes to complete the probable prime (PRP) test using GeneferOCL2. Viktor Svantner is a member of the**Czech National Team**team. The PRP was confirmed prime by an Intel(R) Xeon(R) CPU E3-1240 v6 @ 3.70GHz with 4GB RAM, running Linux Debian. This computer took about 6 hours, 6 minutes to complete the primality test using LLR. For more details, please see the**official announcement**.
Kategórie: Novinky z projektov

### GFN-262144 Find!

On 12 February 2020, 14:26:58 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime:

**9750938^262144+1**The prime is 1,832,137 digits long and enters Chris Caldwell's**The Largest Known Primes Database**ranked 15th for Generalized Fermat primes and 86th overall. The discovery was made by Alen Kecic (**Freezing**) of Germany using an NVidia GeForce GTX 1660 Ti in an Intel(R) Core(TM) i7-7820X CPU @ 3.60GHz with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition. This GPU took about 22 minutes to complete the probable prime (PRP) test using GeneferOCL2. Alen Kecic is a member of the**SETI.Germany**team. The prime was verified on 12 February 2020, 14:32:50 UTC by Tom Greer (**tng***) of the United States using an NVidia GeForce RTX 2080 in an Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz with 16GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 13 minutes to complete the probable prime (PRP) test using GeneferOCL2. Tom Greer is a member of the**Sicituradastra.**team. The PRP was confirmed prime by an Intel(R) Xeon(R) CPU E3-1240 v6 @ 3.70GHz with 4GB RAM, running Linux Debian. This computer took about 13 hours, 22 minutes to complete the primality test using LLR. For more details, please see the**official announcement**.
Kategórie: Novinky z projektov

### Rosetta's role in fighting coronavirus

Thank you to all R@h volunteers for your contributions to help accurately model important coronavirus proteins. The collective computing power that you provide through R@h helps academic research groups world wide model important protein structures like these.

From a recent IPD news post:

"We are happy to report that the Rosetta molecular modeling suite was recently used to accurately predict the atomic-scale structure of an important coronavirus protein weeks before it could be measured in the lab. Knowledge gained from studying this viral protein is now being used to guide the design of novel vaccines and antiviral drugs."

Since the release of SARS-CoV-2 genome sequences in late January, a number of important corona virus proteins like the one described above have been modeled on R@h volunteer computers. A list of these proteins is provided by the Seattle Structural Genomics Center for Infectious Disease (SSGCID).

Kategórie: Novinky z projektov

### Experiment queue being filled up

There should be plenty of work in workunits of the "MDADpr4" series. It should be one of the largest efforts so far.
T

Kategórie: Novinky z projektov

### Thanks for supporting SixTrack at LHC@Home and updates

Dear volunteers,

All members of the SixTrack team would like to thank each of you for supporting our project at LHC@Home. The last weeks saw a significant increase in work load, and your constant help did not pause even during the Christmas holidays, which is something that we really appreciate!

As you know, we are interested in simulating the dynamics of the beam in ultra-relativistic storage rings, like the LHC. As in other fields of physics, the dynamics is complex, and it can be decomposed into a linear and a non-linear part. The former allows the expected performance of the machine to be at reach, whereas the latter might dramatically affect the stability of the circulating beam. While the former can be analysed with the computing power of a laptop, the latter requires BOINC, and hence you! In fact, we perform very large scans of parameter spaces to see how non-linearities affect the motion of beam particles in different regions of the beam phase space and for different values of key machine parameters. Our main observable is the dynamic aperture (DA), i.e. the boundary between stable, i.e. bounded, and unstable, i.e., unbounded, motion of particles.

The studies mainly target the LHC and its upgrade in luminosity, the so-called HL-LHC. Thanks to this new accelerator, by ~2035, the LHC will be able to deliver to experiments x10 more data than what is foreseen in the first 10/15y of operation of LHC in a comparable time. We are in full swing in designing the upgraded machine, and the present operation of the LHC is a unique occasion to benchmark our models and simulation results. The deep knowledge of the DA of the LHC is essential to properly tune the working point of the HL-LHC.

If you have crunched simulations named "workspace1_hl13_collision_scan_*" (Frederik), then you have helped us in mapping the effects of unavoidable magnetic errors expected from the new hardware of the HL-LHC on dynamic aperture, and identify the best working point of the machine and correction strategies. Tasks named like "w2_hllhc10_sqz700_Qinj_chr20_w2*" (Yuri) focus the attention onto the magnets responsible for squeezing the beams before colliding them; due to their prominent role, these magnets, very few in number, have such a big impact on the non-linear dynamics that the knobs controlling the linear part of the machine can offer relevant remedial strategies.

Many recent tasks are aimed at relating the beam lifetime to the dynamic aperture. The beam lifetime is a measured quantity that tells us how long the beams are going to stay in the machine, based on the current rate of losses. A theoretical model relating beam lifetime and dynamic aperture was developed; a large simulation campaign has started, to benchmark the model against plenty of measurements taken with the LHC in the past three years. One set of studies, named "w16_ats2017_b2_qp_0_ats2017_b2_QP_0_IOCT_0" (Pascal), considers as main source of non-linearities the unavoidable multipolar errors of the magnets, whereas tasks named as "LHC_2015*" (Javier) take into account the parasitic encounters nearby the collision points, i.e. the so called "long-range beam-beam effects".

One of our users (Ewen) is carrying out two studies thanks to your help. In 2017 DA was directly measured for the first time in the LHC at top energy, and nonlinear magnets on either side of ATLAS and CMS experiments were used to vary the DA. He wants to see how well the simulated DA compares to these measurements. The second study seeks to look systematically at how the time dependence of DA in simulation depends on the strength of linear transverse coupling, and the way it is generated in the machine. In fact, some previous simulations and measurements at injection energy have indicated that linear coupling between the horizontal and vertical planes can have a large impact on how the dynamic aperture evolves over time.

In all this, your help is fundamental, since you let us carry out the simulations and studies we are interested in, running the tasks we submit to BOINC. Hence, the warmest "thank you" to you all!

Happy crunching to everyone, and stay tuned!

Alessio and Massimo, for the LHC SixTrack team.

All members of the SixTrack team would like to thank each of you for supporting our project at LHC@Home. The last weeks saw a significant increase in work load, and your constant help did not pause even during the Christmas holidays, which is something that we really appreciate!

As you know, we are interested in simulating the dynamics of the beam in ultra-relativistic storage rings, like the LHC. As in other fields of physics, the dynamics is complex, and it can be decomposed into a linear and a non-linear part. The former allows the expected performance of the machine to be at reach, whereas the latter might dramatically affect the stability of the circulating beam. While the former can be analysed with the computing power of a laptop, the latter requires BOINC, and hence you! In fact, we perform very large scans of parameter spaces to see how non-linearities affect the motion of beam particles in different regions of the beam phase space and for different values of key machine parameters. Our main observable is the dynamic aperture (DA), i.e. the boundary between stable, i.e. bounded, and unstable, i.e., unbounded, motion of particles.

The studies mainly target the LHC and its upgrade in luminosity, the so-called HL-LHC. Thanks to this new accelerator, by ~2035, the LHC will be able to deliver to experiments x10 more data than what is foreseen in the first 10/15y of operation of LHC in a comparable time. We are in full swing in designing the upgraded machine, and the present operation of the LHC is a unique occasion to benchmark our models and simulation results. The deep knowledge of the DA of the LHC is essential to properly tune the working point of the HL-LHC.

If you have crunched simulations named "workspace1_hl13_collision_scan_*" (Frederik), then you have helped us in mapping the effects of unavoidable magnetic errors expected from the new hardware of the HL-LHC on dynamic aperture, and identify the best working point of the machine and correction strategies. Tasks named like "w2_hllhc10_sqz700_Qinj_chr20_w2*" (Yuri) focus the attention onto the magnets responsible for squeezing the beams before colliding them; due to their prominent role, these magnets, very few in number, have such a big impact on the non-linear dynamics that the knobs controlling the linear part of the machine can offer relevant remedial strategies.

Many recent tasks are aimed at relating the beam lifetime to the dynamic aperture. The beam lifetime is a measured quantity that tells us how long the beams are going to stay in the machine, based on the current rate of losses. A theoretical model relating beam lifetime and dynamic aperture was developed; a large simulation campaign has started, to benchmark the model against plenty of measurements taken with the LHC in the past three years. One set of studies, named "w16_ats2017_b2_qp_0_ats2017_b2_QP_0_IOCT_0" (Pascal), considers as main source of non-linearities the unavoidable multipolar errors of the magnets, whereas tasks named as "LHC_2015*" (Javier) take into account the parasitic encounters nearby the collision points, i.e. the so called "long-range beam-beam effects".

One of our users (Ewen) is carrying out two studies thanks to your help. In 2017 DA was directly measured for the first time in the LHC at top energy, and nonlinear magnets on either side of ATLAS and CMS experiments were used to vary the DA. He wants to see how well the simulated DA compares to these measurements. The second study seeks to look systematically at how the time dependence of DA in simulation depends on the strength of linear transverse coupling, and the way it is generated in the machine. In fact, some previous simulations and measurements at injection energy have indicated that linear coupling between the horizontal and vertical planes can have a large impact on how the dynamic aperture evolves over time.

In all this, your help is fundamental, since you let us carry out the simulations and studies we are interested in, running the tasks we submit to BOINC. Hence, the warmest "thank you" to you all!

Happy crunching to everyone, and stay tuned!

Alessio and Massimo, for the LHC SixTrack team.

Kategórie: Novinky z projektov

### LHC@home down-time due to system updates

Tomorrow Wednesday 24/1, the LHC@home servers will be unavailable for a short period while our storage backend is taken down for a system update.

Today, Tuesday 23/1, some of the Condor servers that handle CMS, LHCb and Theory tasks will be down for a while. Regarding the on-going issues with upload of files, please refer to this thread.

Thanks for your understanding and happy crunching!

Today, Tuesday 23/1, some of the Condor servers that handle CMS, LHCb and Theory tasks will be down for a while. Regarding the on-going issues with upload of files, please refer to this thread.

Thanks for your understanding and happy crunching!

Kategórie: Novinky z projektov